MEXICO CITY, May 22, (AP): At least four people were involved in the killing of the personal secretary and a close adviser of Mexico City ’s Mayor Clara Brugada, the capital’s police chief said Wednesday, as more details emerged of the worst attack against public officials in the capital in recent years. Pablo Vázquez Camacho said investigators had identified and found a motorcycle and two other vehicles used in the escape of the gunman who killed the two officials Tuesday morning as they traveled in a vehicle along a busy thoroughfare.

Brugada's personal secretary, Ximena Guzmán, and an adviser, José Muñoz, were shot dead in Guzmán’s car, authorities said. Mexico City chief prosecutor Bertha Alcalde Luján said the gunman had fled on a motorcycle that was hidden nearby and then changed vehicles twice as he and others fled into neighboring Mexico State.

Clothes were recovered in the vehicles and were being analyzed, but investigators could not yet offer a possible motive, the prosecutor said. She said Guzmán was shot eight times and Muñoz four times. Alcalde said that given the circumstances, investigators believe "it was a direct attack and with an important degree of planning and those who killed them had previous experience.” Still, she said investigators could not yet propose a motive or say who was behind the killings.

"We cannot conclude that this is tied to organized crime, much less speak now of a particular organized crime group,” Alcalde said. Both officials said Wednesday that investigators had detected the presence of an individual at the site of the attacks days before they occurred, which would suggest knowledge of the victims' routines.

The attack, which happened at around 7 a.m., left four bullet holes clustered on the driver’s side of the windshield. One body lay on the pavement. Vázquez Camacho said that neither Guzmán nor Muñoz had any special security measures, but both had received training about protecting themselves. "They are people who worked very closely with the people ... and they did their work without fear,” he said. President Claudia Sheinbaum, who is an ally of Brugada and a former mayor of Mexico City before winning the presidency last year, had declined to speculate on the possible involvement of organized crime during her press briefing earlier Wednesday.